Yarn tension



D. A; TEBO YARN TENSION June 7, 1938.

Filed Jan. 26, 1937 2 Sheets-Sheet 2 flavzlcz 62-13 50 W, M 14... of?

Patented June 7, 1938 UNITED STATES YARN TENSION David A. Tebo, Lawrence, Mass,

assignor to U S Bobbin & Shuttle Company, Manchester, N. 11., a corporation of Rhode Island Application January 26, 1937, Serial No. 122,336

4 Claims.

This invention pertains to weaving shuttles and relates more particularly to shuttle tensions. While in certain of its aspects the present invention is of broader utility, it is especially valuable in' association with yarn take-up devices such as are sometimes provided for taking up the slack in the yarn as the shuttle enters the box at one side or the other of the loom, thereby toavoid the interweaving of kinked yarn during the next pick of the shuttle.

When such a take-up is used, it is essential to its effective operation, that the yarn acted upon by the take-up be that which extends from the shuttle toward the fell of the cloth. However, unless a dependable restraining device be interposed between the bobbin and the take-up, the action of the take-up may be merely to draw off additional yarn from the bobbin, instead of applying tension to the yarn which extends. out through the shuttle eye, thus defeating the purpose of the take-up. A principal object of the present invention is to provide efiective means operative to prevent free withdrawal of yarn from the bobbin by the operation of they take-up.

Preferably, the means for preventing withbut also to apply the desired tension to the yarn,

as the latter is drawn off from the bobbin during the flight of the shuttle.

In shuttles where a take-up is used, a large portion of the available space between the tip of the shuttle and the bobbin chamber must be reserved for the reception and operative movement of the take-up parts, and thus any tension designed for use between the take-up and the bobbin must be of relatively small external dimensions. 'Accordingly a further object of the invention is to provide a practical tension device effective for its intended purpose but at the same time of such small dimensions as to permit its installation in a normal commercial type of shuttle in the bobbin andthe delivery of kin ked, knotted or drawal of the yarn'from the bobbin by the takeabnormally twisted yarn into the fell of the cloth, Q

and a further object of the present invention is to provide a shuttle tension capable of applying such uniform and effective tension to the yarn even though of wiry, kinky character as to prevent excessive and kinked yarn from being delivered from the shuttle eye.

For use inweaving such a wiry yarn as artificial silk, flat or blade-like bobbins have recently come into use, said bobbins being wider transversely than vertically as disposed in the shuttle chamber. Thus in leaving the bobbin tip, the yarn balloons in a horizontally elliptical path rather than in the usual circular path. In consequence, for most effective operation and to avoid excessive Wear, any tension employed for controlling yarn ballooning in this way should be so designed as to facilitate the approach of yarn thereto through a horizontal angle of substantial extent. A furtherobject of the invention is to provide a tension which may be disposed so as to be capable ofreceiving and tensioning yarn with substantially equal efficiency whether the yarn balloons in an elliptical path as when a flat bobbin is used, 'or balloons in a circular path resulting from the employment of a bobbin ofgenerally cylindrical shape.

Further objects of the invention are to provide a tension device which may readily be secured firmly in the shuttle body; to provide a tension device which imposes substantially uniform tension on the yarn at all times; to provide a tension device having yarn-engaging parts which do not readily wear and which are not easily cut or scored by the running yarn, especially yarns which are hard twisted, or of silk or artificial silk. A further object of the invention is to provide a yarn tension such that the tension applied to the yarn may readily be adjusted without removing the tension device as a' whole from the shuttle; and to provide a tension device of simple, durable and cheap construction which may be manufactured at low cost; which may readily be installed in the shuttle; and which has a useful life substantially as long as that of the shuttle itself.

Other objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompany ing drawings, wherein Fig. 1 is a plan view of a shuttle embodying the present invention; r. I

Fig.- 2 is a fragmentary side elevation ,of the shuttle of Fig. 1, drawn to. larger scalefandshowing a take-up device. installed within the forward end of the shuttle body; 7

Fig. 3 is a fragmentary horizontal section, to larger scale, substantially on the line 33 of Fig. 2; V

Fig. 4 is a fragmentary vertical section substantially on the line 4-4 of Fig; 3;

' Fig. 4 is a section on the line 4 4 of Fig. 3; Fig. 5 is a rear elevation of the tension device of Fig. 3 shown removed from the shuttle body; Fig. 6 is an end elevation, partly in vertical section, of the tension device of Fig. 5;

Fig. 7 is a plan view of the tension device of Figs. 5 and 6; ,7

Fig. '7 is a perspective View, to large, scale, of one of the yarn-tensioning friction pads;

Fig. 8. is a fragmentary longitudinal section through the forward part of the shuttle of Fig. 1, illustrating one desirable means of securing the tensionin'place within the shuttle body; Fig. 9 is a transverse'section througha shuttle body atthe forward end'of the bobbin chamber,

showing a shuttle eye such as that of Fig. 5 dismode of securing the tension device'in position a b y;

in the shuttle body;

. Fig. 11 is a fragmentary plan view illustrating I a tension device of modified form embodying the present invention;

' Fig. 12 is a fragmentary vertical section sub Fig. 14 is an'end elevation of 'the tension-device of Fig. 13; and I V Fig. 15 is a plan View of the tension device shown in Figs. 11 to '14 inclusive.

Referring to the drawings, the numeral I desig- 'and 3, the bobbin is a flat bobbin 'of the type which has been'found highly desirable forfuse with yarns of artificialsilk or" the like, the 'wider faces of the bobbin being normally disposed in substantially horizontal planes] The. yarn Y forming the yarn mass 5 on the bobbin is (during forward'end 6 of the latter.

the'normal weaving operation), drawn off over the "tipof the bobbin, and is delivered from an eye or opening in the side of the shuttle at the This forward end, as herein illustrated, is provided with a chamber :or cavity I designed to receive a take-up 'device.

The take-up device, s here illustrated, co inprises alength-of wire bent to form an elongate take-up arm 8, anda portion coiled to'embr'ace the pivot pin 9. This'length' of wire also comprises a portion'IO forming a short arm to'which isjconnected one end of aspring'element 'I I, for example; a length of rubber elastic whose other end; is anchored to the post I2, the normal tend ency of the-spring I'I being to swing the arm-8 i toward the .dotted 'position of Fig- 3. The arm 8 is furnished with a series of thread-engaging 'loops- I3; which" cooperate with interposed fixed posts'll l to draw'the' yarn into a zigzagpath when 7 the arm ,8is swung toward the dotted'linejposition,i"thus tending to take up any slack in the of the part 21.

- trated in Fig. 4 this bore I9 is of more or less elliptical form with its longer axis substantially horizontal. yarn-restraining and tensioning device 20. This f yarn-restraining and tensioning, device; in ac-' cordance with the present invention, preferably This bore is designed to receive'a comprises a block 2|] of any suitable material, such for example, as brass, bronze, aluminum, steel, porcelain or one of the'synthetic resins (for example phenol-formaldehyde) and may be shaped in any appropriate way, as by machining, die casting, moulding or the'like. This block is externally dimensioned to fit snugly. within the opening I9,. if desiredwith a drivingfit; so that no other retaining meansv may be necessary to hold it firmly in place. The block is provided with a horizontal yarn passage extending from front to rear, and, as illustrated in Fig. 6, com- 1 prising the spaced parts 2I and ZI verse'slot 22 intersects this yarn passage, the en- A trans-,

30 trance endfof the passage "preferably being smoothly rounded or flared, as shown in 2H, to

Theiexit end of horizontal. plane of the axis of the bobbin when the tension device is mounted within theshuttle. Adjacent'to the right and left-hand ends of the yarn passage, posts 23 and 24, respectively,

project upwardly from" the bottom wall ofth'e slot 22, the posts being fixed ,in' the material of upper ends free. These posts constitute guiding and retaining means for a pair of yarn-engaging elements 26 and32 designed 'to receive the yarn between them as it passes out from. thebobbin chamber into the take-up chamber Land to apiply frictional restraint to the yarn at a point.

between the bobbin and the take-up These redisposed substantially horizontal, as shown in Figs. 4, 5 andfi, with their opposed yarn-contacting surfaces substantially in the horizontal plane 7 of the bobbin axis; Each of these elements pref erably consists of a piece of sheet metal (Fig. 7) having a transversely elongate central part 21, the outer surface of which contacts with the yarn. The piece also comprises front and rear inclined or .beveled portions 28 and 29 designedto'guide the yarn on its way to. and from the outer surface Each of these elements or. friction'pads26 and 32 is furnished with a pair of openings 30 and 3| adjacent to'its opposite ends, and when the pads are disposed within the slot 22 of the tensioning block, the pins 23 and 24 pass freely through these openings.

The two tensioning and restraining pads 26 and 32 are substantially identical in shape and size,-but are the block at their lower ends but having their j straining and tensioning elements are preferably so disposed within'the slot 22 that the inclined or; beveled edges of the two tension pads e01: lectiyely form flaring-guide'throats 33 and 34 for directing the yarn into and out of contact with 7 the substantially .horizontal central portions of if the members 26 and 32. The tensioning and restraining pads 26 and 32 may be of any suitable material such, for example, as sheet steel which may be heat treated or otherwise hardened, or of a wear-resistant alloy, or which may be of porcelain, glass or any other suitable materialnot readily cut or scored by the passing yarn. It may be noted that by the use of yarn-tensioning elements, which are elongate in the direction of the major axis of the ellipse formed by the yarn as it balloons from the end of the flat bobbin, the yarn is permitted to move transversely from one side to the other of its general path of movement, that is to say, transversely of the fro-nt-to-rear direction, so that the wear is distributed and so that, in fact, the moving yarn tends to polish the opposed surfaces of the tension elements rather than to cut definite grooves or channels therein.

Interposed between the under surface of the member 26 and the bottom of the slot 22 are resilient cushioning elements such as coiled springs 26 These springs are conveniently arranged to embrace the'posts 23 and 24, thereby holding the springs in proper position so that they act at all times to cushion the lowermost pad 26, permitting the latter to yield downwardly either at one or both ends during use.

The material of the shuttle body immediately above the location of the slot 22 is provided with a bore 35, (Fig. 4), in which is disposed a tension-adjusting screw 36 having an axial positioning nib which enters the upper part of a coiled tension spring 31, the lower end of which bears upon the upper surface of the tensioning pad 32 at a point substantially midway between the posts 23 and 24.

While it ordinarily suflices to press the tensioning block 20 into position in the bore IQ of the shuttle body, it is contemplated that more positive retaining means may be provided if desired. Thus, as illustrated in Fig. 8, the material of the shuttle body may be furnished with a bore 38 extending upwardly from the under side of the shut tle and which receives a set screw 39 whose upper end bears against the under side of a block 20 thus furnishing additional means for retaining the block in position. V w

As illustrated in Fig. 9, it may be desirable under some conditions, for example when a bobbin of the usual substantially cylindrical type is employed, to place the tension block 2|! with its longer axis vertical. In this event the bore in the wall l8 of the shuttle will be arranged with its longer axis vertical, and, after positioning the block 2!! in this bore, the block may be positively held in position, if necessary, by means of a set screw 40 disposed in a bore 4| leading inward from a side wall of the shuttle.

In Fig. 10 other-means for holding the block positively in position is shown. In this case the block 20 is furnished with a pair of semi-cylindrical recesses at its opposite ends and these recesses receive pins 42 and 43 which are driven vertically down through the material of the shuttle body so as to engage the recesses in the block.

While the block shown in Figs. 4 and 7, inclusive, represents a preferred construction, it is contemplated that the tension block may be made in other ways within the scope of the invention. For example, as illustrated in Figs. 11 to 15, inclusive, the tension device 2|) comprises a block 44 having the yarn passage 45 extending from front to rear and preferably of more or less elliptical transverse section with its major axis horizontal and normally disposed substantially in the'plane of the bobbin axis. This yarn passage is furnished with a flaring entrance throat,

but in thisinstance is intersected by a transverse slot 46which opens at the rear edge of the block. Pins 41 and 48 pass through openings in the upper and lower walls of the slot 46, these pins being disposed adjacent to the ends'of the major midway between the pins 47 and 48, and after the tension block has been mounted in the shuttle body (Fig. 12), a coiled tensioning spring 54 is dropped down through a suitable bore 55 in the material of the shuttle body and is then placed under compression by means of a tensionadjusting screw 56. For positively holding the block in position in the shuttle body, a set screw 51 may be arranged to pass down through the material of the shuttle and to engage the upper surface of the block 44. V

In the operation of. the device, for example'as illustrated in Figs. 1 to 8, the yarn Y is drawn off from the yarn mass on the bobbin and is first threaded between the tensioning members 26 and 32 (by means of a suitable hook or needle) and through the several loops l3 of the take-up device, and then passes out through the shuttle eye defined by the fixed pins I6 and H. By turning the tensioning screw 36, the pressure exerted by the spring 3'! upon the upper tensioning member 32, may be so adjusted as to provide the desired frictional pressure upon the yarn during the weaving operation. By cushioning the tension member 26 upon the laterally spaced springs 26*, and by applying the tensioning pressure by means of a centrally disposed single spring 37, a very uniform tension is secured. As already noted, the approaching yarn, although its angle of approach varies very substantially in unwinding from the flat bobbin, is always free to move through the yarn passage (without encountering any deflecting obstacle) by reason of the transversely elongate shape of the tensioning elements, and thus there is no tendency to crimp the yarn or cause variations in tension as the yarn pulls off from the bobbin. Furthermore, by reason of the cushioning of both of the tension-applying members 26 and 32, their opposed yarn-engaging surfaces may rock transversely in unison, maintaining their substantially parallel relation at all times, and in this way tend to maintain uniformity of tension and at the same time gently to grip and smooth the yarn and then to straighten out knots or kinks which approach the tensioning device. In fact this tensioning device is highly efiective in preventing the passage of abnormal twists or kinks from the bobbin chamber to the take-up chamber. By the use of yarn-engaging tensioning surfaces of the substantial extent afforded by the device here illustrated, it is possible to restrain the yarn and apply tension thereto by theme of a relatively gentle pressure of the spring 31. This spring is so adjusted that when the take-up arm acts as the shuttle enters the box at one side or the other of the loom, the yarn is held back'by the tension device. so that'all of the slack which is then taken up by' the take-up'device is that which extends from the exit'end of the tension toward the fellof the cloth. This provides for a satisfactory operation of the take-up such as can not be secured unless restraining means be interposed between the take-upand the bobbin,

In the tension device of Figs. 4' to '7; inclusive, the tensioningelements 26 and 32 maybe removedtfrom the, block after the latter'has been withdrawn from the'shuttle body merely by liftthe pins 41 and 48.

, ing them from off the pins 23 and 24, thus permitting the ready replacement of these tensioning members, ifworn. On the other hand, to remove the tensioning members 5!) and 5| from the block M of Figs. 12 to 15, his necessary first to remove However; these pins need i not be fixed within the block, since, after the block has been installedin'the body of the shuttle', these pins can not escape even though seated within the block with a sliding fit.

While certain desirable embodiments of the 'invention'have hereinbeen illustrated by way of 'Zexample, it is to' be 'understood that the invention .is not to be limited to these precise constructions but is to be regarded as inclusive of all equivalents falling within the scope of the appended claims. b V f V I claim: 1, l. A shuttle of the' kind havin'gthereina bob- "bin chamber and a take-up chamber separatediromthebobbin chamber by a transverse wall, said wall having thereinan aperture disposed fwholly below the top surface of the shuttle,'

characterized in having a tension device comprising a block fitting snugly within said aperture and'having a recess at one, at least, of its ends,

and a retaining element fixed within the shuttle .body and entering said re'cess thereby positively to hold the'b-lock inoperative position, and tension elements housediwithin the block. b

2. A shuttleof the kind having therein-a bobbiirchamber; a. second chamber separated irom the bobbin chamber by a transversewall, and a tension device comprising a housing set in an aperture in said wall, characterized in that said aperture is of substantially elliptical contour in transverse vertical section with its longer axis substantially horizontal, the housing being of such external shapeand dimensions as to fit snugly within saidaperture and having a yarn passage leading from one chamber to the other,

said passage being provided with'a substantially elliptical entrance throat, and a pair of yarnengagingpads disposed within the housing, said pads being elongate widthwise of the shuttle.

3. A-shuttle of the kind having therein a bob bin chamber and a take-up chamber separated frorn'the bobbinchamber by a transverse wall, and means within the bobbin chamber forholding .a fiat bobbin with its wider faces substantially horizontal, characterized in having a tension block fixed in an aperture in said'transverse' wall, the block having'a transversely elongate yarn passage disposed substantially in the plane of the tip portion of a flat bobbin mountedin the bobbin chamber, a pair of friction pads housedwithinthe block, said padshaving opposed yarn-engaging surfaces normally disposed substantially in the horizontal plane of the axis of the bobbin, said pads being elongate widthwise ofthe shuttle thereby to permit free transverse deviation ofithe yarn as it approaches'the tensioning device in ballooning from the, tip of the bobbin, guide means engaging the pads at transversely spaced'points, said guidemeans being so designed and arranged as to permit the two pads to tilt laterally in unison in either direction, resilient cushioningfmeans engaging, the outer surface ofone' padadjacent to its opposite ends respectively, and a tension-applying spring engaging the outer surface of the a other pad substantially midway between its ends.

4. A shuttle of the kind having therein a bobbin chamber and 'a' second chamber separated from the bobbin chamber by a transverse wall, the latter having an aperture'connecting the two chambers,and means'within'the bobbin chamber for holding a flat bobbin with its wider faces-substantially horizontal, characterized in having a tension block fixed in the aperture in said'transverse wall, the block having a transversely elongate yarn passage, a pair of friction pads housed within the block, said pads having opposed yarnengaging surfaces normally disposed substantially in the ho'rizontaliplane of the axis of the bobbin, said pads being elongate transversely of the shuttlethereby to permit free transverse de- I viation of the yarn as it approaches the tensioning device in ballooning'from the tip of the bobbin, means operative to hold the pads in registering relation while permitting them freely to move toward and from each'other, resilient cushioning'meansfor one of the pads, a tensionapplying spring engaging the other pad, {and means accessible fromtheiexterior of the shuttle,

for varying the tension ,force applied by said spring. I

DAVID A. TEBOL 

